Chromatographic investigations of estradiol receptor from breast cancer tissue

DEAE-cellulose chromatography of non-activated and activated estradiol receptors yields a different, characteristic elution pattern. This chromatography should therefore be able to demonstrate the presence of intact receptors. For clinical receptor investigations, it is usual to select arbitrary cut-off values for receptor quantity and Kd to classify into receptor positive and negative cases. DEAE-cellulose chromatography confirmed the results obtained by such classification in most cases, except those which had been classified as negative on the basis of Kd values higher than 2 nM. In these cases, DEAE-cellulose chromatography indicated the presence of estradiol receptors and therefore a misclassification of the measured results. Thus DEAE-cellulose chromatography can contribute to a clarification of the equivocal results. On the other hand, we did not get any indications of damages to the receptor molecule which in our previous investigations were found to be the result of violent homogenization procedures.